Horizontal tube knitting machine



HORIZONTAL TUBE KNITTING MACHINE Filed April 18, 1942 8 Sheets-Sheet 1 y W, IM

March 7, 1944. w. LARKIN 2,343,776

HORIZONTAL TUBE KNITTING MACHINE March 7, 1944.

w. LARKIN 2,343,776

HORIZONTAL TUBE KNIITING MACHINE Filed April 18, 1.942 8 Sheets-Sheet 3 March 7, 1944. w- LARKlN 2,343,776

HORIZONTAL TUBE KNITTING MACHINE 8 Sheets-Sheet 5 W. LARKIN HORIZONTAL TUBE KNITTING MACHINE 2,2 .kf/4# ...--J .f .E

Filed April 18, 1942 March 7, 1 944.

8 Smeets-Shea*l 6 March 7, 1944. w. LARKIN HORIZONTAL TUBE KNITTING MACHINE Filed April 18, 1942 March 7, 1944. w. LARK|N` HORIZONTAL TUBE KNITTING MACHINE Filed April 18, 1942 8 Sheets-Sheet '7 March 7, 1944. w LARKlN 2,343,776

HORIZONTAL TUBE KNITTING MACHINE Filed April 18, 1942 8 Sheets-Sheet 8 Patented Mar. 7, 1944 HORIZONTAL TUBE KNITTING MACHINE Walter Larkin, Norristown, Pa., assigner to Fideiity Machine Company, Philadelphia, Pa., a corporation of Delaware Application April 18, 1942, Serial No. 439,572

(Cl. Gli- 9) 4 Claims.

This invention relates to a machine for knitting a seamless tubular fabric jacket about a central core in the manufacture of rubber hose. flexible tubing, cable insulation, and so forth.

In the present instance, the invention is disclosed as being employed in the manufacture of rubber hose or flexible tubing according to the principles set forth in my prior U. S. Patent, No. 2,264,213, dated November 25, 1941, while using a knitting head of the type shown in my prior U. S. Patent No. 2,259,384, dated October 14, 1941.

The object of the present invention is to provide a knitting machine wherein the axis oi the knitting head is disposed horizontally, or substantially so, to meet certain requirements in the manufacture of rubber hose, for example, wherein a rubber core tube is rst placed on or formed around a suitable mandrel having the form of a longitudinally elongated rod-like structure. and wherein a fabric reinforcement is placed or formed around the core tube, prior to the application of an outer layer of rubber thereto, while the mandrel, due to its length and rigidity, is necessarily retained in a horizontal position,

In the present instance, the fabric reinforcement is knitted around and in close contact with the outside of the core tube, while the mandrel advances longitudinally through the knitting machine in a horizontal plane.

In the present instance, the knitting machine includes a. novel feeding means and take-off means for controlling the passage of the mandrel and the core tube into one end of, through, and out the opposite end of the knitting head; it being noted that these mandrels are normally in excess of 50 feet in length for making rubber hose in 50 foot sections. However, these lengths may be increased or decreased according to requirements without departing from the spirit ofthe invention.

The construction and operation of the machine will be fully disclosed hereinafter, references being had to the accompanying drawings of which:

Fig. 1 is a side elevation;

Fig. 2 is a left end elevation;

Fig. 3 is a right end elevation;

Fig. 4 is a plan view:

Fig. 5 is a sectional elevation of the knitting head, enlarged;

Fig. 6 is a sectional elevation, enlarged, of the feed end of the machine;

Fig. 7 is a sectional elevation, enlarged, of the take-off end of the machine;

Fig. 8 is a sectional elevation of the driving mechanism for the take-oil! rolls, the section being taken on the line 8-8, Fig. 4;

Fig. 9 is the sectional view taken on the line 9 9, Fig. 8;

Fig. 10 is a detached perspective view of the ratchet clutch drive for the take-oil rolls;

Fig. l1 is a sectional view through th ratchet clutch shown in Fig. 10, taken on the line III-III, Fig. 8:

Fig. 12 is a diagrammatic perspective view of a stop motion employed in the machine;

Fig. 13 is an end elevation, partly in section, of the broken thread detecting mechanism of the stop motion;

Figs. 14 and 15 illustrate details of the ap.- paratus shown in Fig. 13;

Fig. 16 is a partial sectional elevation illustrat-l ing the broken needle or knot detecting mechanism of the stop motion;

Figs. 17 and 18 illustrate details of the apparatus shown in Fig. 16;

Fig. 19 is an end elevation of the brake mechanism of the stop motion;

Figs. 20 and 21 illustrate details of the apparatus shown in Fig. 19; and

Figs. 22 and 23 illustrate details of the power clutch mechanism of the stop motion.

As previously noted, the knitting head of the present machine corresponds with that disclosed in the aforesaid U. S. Patent No. 2,259,384, and is particularly adapted for knitting tubes of relatively small diameters, with the stitch wales of the fabric disposed in close lateral relation to each other, to produce a compact fabric in close firm contact with the rubber core tube C carried by the mandrel M as the two move concurrently through the knitting head I.

The knitting head I is supported at one end by a tubular shaft 2, and at its opposite end by a tubular shaft 3; said shafts being in axial alignment with each other and rigidly supported by end frames 4 and 5 of the machine (see Figs. 6 and 7). The knitting head (see Fig. 5), comprises a pair of identical needle cylinder units A1 and A2, respectively secured, at one end of each unit, to the tubular shafts 2 and 3.

Each of the cylinder units A1 and A2 comprises an outer part I0 and an inner part II, concentrically arranged. The outer part I0 is in the form of a hollow cylinder or sleeve and is provided with an annular shoulder I2 4which is adapted to rest against the inner end I3 of the tubular shaft 2 or 3, as the case may be. Beyond the shoulder I2, each outer cylinder element' I0 is reduced in diameter to form a neck I4, which is adapted to fit snugly into the supporting tube 2 or 3. Any suitable means may be provided for securing the outer cylinder element I to its supporting tubular shaft such, for example, as by screws I5.

Each of the outer cylinder elements I0 is provided, on its outer peripheral surface, with a plurality of axially extending needle grooves Il, in planes radiating from the axis of said element.

The grooves I6, I6 are spaced apart circumferentially of the element I0, with partitions i1, I1 therebetween. The base surfaces I8 of the needle grooves I6 are disposed at an angle to the axis of the element I0 and converge toward a work slot :i: formed by and between the adjacent ends of the inner parts II, of the units A1 and A2, respectively.

The inner element of each of the cylinder units A1 and A2 is composed of a relatively thin tube 25, which is adapted to iit snugly within the interior bore of the outer element I0. One end of the tube in each instance is provided with an annular `flange 21 which is adapted to bear against the end surface 28 of the neck I4, to

which said flange is secured by screws or bolts 29.

The opposite end of each of the inner elements I I, i. e., the end adjacent the work slot x, is circumferentially beveled, as indicated at 30, on an angle corresponding to that of the base surfaces I8 of the needle grooves I6 in the outer element p' I0, for supporting the needles 20, immediately adjacent the work slot when said needles are moved longitudinally in the slots |6, with their hooked ends crossing the work slot :c during the knitting operation.

Beyond the beveled surface 30, each inner element I| is provided with a plurality of circumferentially spaced longitudinally extending recesses or slots 3|. The slots 3| in each of the units A1 and A2 are positioned in alignment with the needle grooves I6 of the other of said units, to receive the hooked ends of the needles 20 when projected across and beyond the work slot zr.

As a result of the above construction, a fabric tube F is knitted in close firm contact with the rubber core tube C, with the stitch wales in close laterally spaced relation to each other to form a close compact fabric around the core tube.

As shown in Fig. 5, the needles 20, 20 are reciprocated in their slots I6, I6, to effect the knitting operation, by ordinary cylindrical cams 40, rotating on the outer peripheral surfaces 4| of the needle cylinder elements I0, I0. The cams 40 are secured, in the usual manner, in cam rings 42, 42. Rotation of the cam rings 42, 42, in unison, is effected by means of posts 5|, 5I which are secured in and project in opposite directions from a ring 55. The ring is secured to a ring 56 which forms part of a rotating frame 60, which revolves about the axis of the tubular shaft 2.

As shown in Fig. 6, the tubular shaft 2 is slidably mounted inV a sleeve bracket 6|, carried by` the end frame 4. Secured to tubular shaft 2, is a ring 6 which is engaged by a clamp 1 for securing the tubular shaft 2 in position. Axial adjustability of the shaft 2 is thus permitted for accurately determining the width of the work slot I. The bracket 6| is provided with an annular shoulder 63, against which the inner race 64 of a ball bearing 65 rests.- The outer race 86 of the ball bearing 65 is fitted in an annular recess formed in a ring gear 61. The rotating frame 50 is provided with an annular base 68 which is secured to the ring gear 51, and by which rotation of the cam rings 42, 42 is effected through the ring 56 of the rotary frame 60.

'Ihe rotary frame 60 is supported for rotation about the tube shaft 2, adjacent the knitting head I, by a ball bearing 10, the inner race 1| of which is tted on the sleeve bracket 6| while the outer race 12 of the ball bearing 10 is fitted in a ring 13 forming part of the rotary frame 60. The ball bearing 10 is spaced from the bali bearing 65 by a sleeve 14, and the ball bearings 65 and 10 are held in position, against axial movement, by a nut 15 threaded onto the projecting end of the sleeve bracket 6|. The inner race 64 of the bearing 65 is thereby held firmly against the annular shoulder 63 of the sleeve bracket 6|.

The ring gear 61 meshes with an idler gear 16, which is secured to one end of a shaft 11. The shaft 11 is rotatably mounted in a bearing 18 carried by the end frame 4. The idler gear 16 meshes with a pinion 19 (see Fig. 2) secured to the main drive shaft of the machine.

The end frames 4 and 5 are held in laterally spaced relation to each other by an upper spacer rod 8| and a pair of lower spacer rods 82, 82 (see Fig. 1). One end of the drive shaft 80 is rotatably mounted in a bearing 83 carried by the end frame 4, while the opposite end of said shaft is rotatably mounted in a bearing 84 carried by or forming part of a bracket or a cross frame 85 which is supported by the spacer rods 82, 82, intermediate the end frames 4 and 5.

Rotatably mounted on the drive shaft 80 (see Fig. 22), is a driving pulley 86, which carries one element 81 of a clutch 88, such for example, as a disc clutch of any suitable kind. Splined to the shaft 80 is a second member 88 of the clutch 88 by which the clutch discs may be engaged and disengaged. Power may be supplied to the driving pulley 86 from any suitable source.

The clutch element 89 is provided with the circurnferentially extending groove 90 for the reception of inwardly projecting elements 93 which are carried by clutch release levers 94 on a clutch controlling shaft 95. The control shaft 85 extends transversely of the machine and is mounted in suitable bearings carried by the frame 85, located intermediate the end frames 4 and 5. The control shaft 95 is also provided wth a suitable control handle 86 (Fig. 2).

Knitting yarn is supplied to the needles 20, 20

by one or more thread guides 81 mounted on the rotating ring 55 by which the cams 40 are rotated about the cylinder units I0 (Fig. 5).

In the present instance, the core element C is placed on or formed around the elongated mandrel M, prior to being inserted into the one end of the knitting machine. The encased mandrel isthen axially aligned with the knitting head I, and is supported in such position, by any suitable means, at the left end of the machine, as viewed in Fig. 1. The encased mandrel is then moved axially until the leading end thereof is engaged by and in the bight of a pair of feed rolls |00, |00 (Fig. 6) which are located out# side the end frame 4. 'I'he rolls |00, |00 advance the encased mandrel through the tubular shaft 2 into and through inner elements II, of the knitting head and through the tubular shaft 3 into the bight 0f a pair of take-off rolls |0I, |0| located outside the opposite end frame 5 (Fig. '1)

The feed rolls |00 and the take-off rolls |0| are of similar construction and are positively driven by similar means, one of which is disclosed in Figs. 8 to 11, inclusive. As shown in Fig. 9, these rolls are provided with circumferential grooves |02, |02, shaped and sized to obtain a ilrm purchase on the outer surface of the assemblage carried by the mandrel M. For example, in the case of thev feed rolls |00, the rubber core element C would be engaged by the in accordance with the knitting speed of the head I, i. e., the number of courses produced per minute by said head. In this manner, the fabric tube F is formed around and along the length of the core tube C.

In the case of the take-off rolls |I, IOI, these rolls would engage the fabric tube F, and rotate in unison with the feed rolls |00 to advance the mandrel, and its assemblage, in the manner noted, until the tail end of the mandrel passed from between the feed rolls |00, |00, after which the axial movement of the mandrel, etc., would be effected entirely by the take-off rolls, IOI, IOI.

Preferably, however, the mandrels are fed into the machine in immediate succession, with the head end of one mandrel butting against the tail end of the preceding mandrel and for all intents and purposes forming a direct continuation thereof, in order that the knitting operation may proceed uninterruptedly. After each mandrel and its assemblage passes out of the bight of the take-off rolls IOI, IOI, the outer fabric jacket F may be severed to release the mandrel from the next succeeding one.

In each instance, each roll |00 and |0|, as the case may be, is rotatably mounted on a fixed stud shaft |03 carried by an adjustable housing |04. Loosely mounted, for free rotation, on each stud shaft |03 is a Worm wheel |05. Each worm wheel is driven by a worm |06 which is rotatably mounted in the frame |04. Each worm |06 is splined to a vertical shaft |01 which passes through the pair of housings |04, |04 associated with the feed rolls |00, or the take-off rolls |0I, as the case may be. 'I'he opposite ends of each of the worms |06 abut against flanged 'bearings |08, |08 which are secured in the housing |04, and by which axial movement of the worm |06 relative to the housing |04 is prevented in each instance. As the rolls |00, |00 or IOI,'I0| of each pair are moved toward or away from each other, to eect engagement with or disconnection from a mandrel passing through the machine, the housings |04, |04 with their enclosedworms |06, |06 will be correspondingly moved. In this manner, mandrels of various diameters may be readily handled by the machine.

Secured to each of the worm wheels |05 is a pawl carrier disc IIO, secured thereto by screws |I I. The worm wheel |05 and disc ||0 in each instance are provided with axially aligned bores I I2 in which are slidably mounted pawl plungers or detents II3 having springs I|4 constantly urging the tooth-like ends II5 of the pawls II3 outwardly Ibeyond the face of the disc H0. The ends |I5 of the pawls II3 are adapted to engage ratchet teeth I I6 formed in one face of a, ratchet disc |I1.

Each ratchet disc I|1 is carried by a hub element IIB, in the form of a sleeve, which is freely rotatably mounted on the stud shaft |03. A

-washer IIS, secured by screw to the end of the stud shaft |03 prevents outwardly axial movement of the hub sleeve I I3 on the stud shaft |03. Each hub element |I3 is provided with a flange I2I, against which the ratchet disc ||1 is fitted and held by screws |22. The heads of the screws |22 project outwardly beyond the flanges |2| in a direction parallel to the axis of the stud shafts |03, to enter recesses |23 formed in adjacent end faces of the rolls |33 or |3I, as the case may be, whereby each roll is keyed to its associated hub element II3 for rotation therewith. The roll is detaehabiy held against axial movement on the hub sleeve I I3 by a washer |24. held in place by the screw |23.

The drive shaft |01 for each pair of worms |06, |06, is rotatably mounted at its lower end in a bracket |25 carried by the end frame 4 or 5, as the case may be. Secured tothe lower end of each of the vertical drive shafts |31 is a miter gear |26.- Each gear |26 meshes with a miter gear |21 secured to a horizontal feed shaft |23 which is rotatably mounted in bearings |29 car-y ried by the brackets |26, |25.

The feed shaft |23 is rotated at a predetermined rate 'of speed, with respect to the speed of rotation of the cam rings 40 of the knitting head I, in order to synchronize the axial movement of the mandrel M etc. with the rotations of the cam rings 40 for producing the desired number of courses of stitches per inch, longitudinally of the mandrel. 'i

In the present instance, the feed shaft |23 is provided, on one end, with a gear |33 which meshes with the gear I3| on the shaft 11 through an idler gear |30a (see Fig. 2). The shaft 11,

as previously noted, is rotated from and by the'A main shaft through the gears 13 and 16. The ratio of the gears |30, |30a and I3I may be varied to suit the spacing of the stitch courses, as desired. Obviously, any suitable speed change mechanism may be substituted for the changeable gears |30 and I3I, as desired, for accomplishing the same purpose. In the present instance, the idler gear I30a is rotatably mounted n a pivot stud 3| which is radially adjustable o the shaft 11 on a bracket 13a which is rotatably adjustable on the 'bearing 13.

In order that the rolls |30 and |0I may receive mandrels of different diameters, or in erder that rolls of different diameters may be employed to grip mandrels of different diameters, the lowermost bushing |03 of each of the housings |04 is provided kwith a screw threaded extension |32 on which is threaded a nut |33. Each of the nuts |33 is provided with a hand-wheel |34, by which the nut may be turned to raise or lower the housing vertically, until the center of radius of the transverse curvature of the circumferential groove of the lower feed or take-off roll, as the case may be, coincides with the axis of the knitting head I.

The upper housing |04, in each instarice, is adapted to slide freely along theshaft I0? with a spring |35 tending to force the housing, and the roll carried thereby, downwardly until the roll makes contact with the mandrel, thereby providing the necessary grip or bight between the cooperating feed or take-off rolls.

The worm gear housings |04 are guided in' their vertical movements along the shafts |01 by posts |36 which are secured in the brackets |25 at their lower ends and in brackets |31 at their upper ends, the top brackets |31 being, in turn, secured to the end frames 4 and 5 and having bearings |33 for the upper ends of the shafts |01.

In order to steady the rotation of the frame 50 and the knitting cams, etc., carried thereby, the ring 53 of said frame is provided with axially extending rods |48, |48 which extend parallel to the axis of the knitting head, with the ends of the rods adjacent the end frame 5 secured in bosses |4| formed on a ring |42 (see Fig. '1). 'I'he ring |42 is provided with an annular cavity in which is mounted the outer race |48 of a bali bearing |44. The inner race |45 of the ball bearing |44- is mounted on one end of a sleeve |46 which is secured in the end frame 5 and provides support for kthe tubular stud shaft 8.

The knitting threads u are drawn from cones yl, 11|, which are supported by arms |48, |40 projecting radially from a ring |48 secured to and rotatable with the rotating frame 60.

From the cones yi, the knitting threads y pass to broken or slack thread detectors |50 which are carried by the rotating ring |42 (see Figs. 13, 14 and 15). Each thread y passes under a slotted arm |5|, formed by a wire bent into the form of a hair pin with the ends of its legs carried by the ring |42, and over a trip lever |52 which lies between said legs and is pivotally mounted at |58 on the ring |42. The trip lever |52 is held, by the thread y, against outward movement under centrifugal force produced by the rotation of the ring |42.

The thread y then passes around a tension or sweep arm |54, which is pivoted to the ring |42 and is rocked in one direction, to place the thread 1l under tension, by coiled spring |55. From sweep arm |54, the thread or yarn y passes through an eye |56 to one of the thread guides 51 carried by the ring 55, adjacent the work slot x.

The trip lever |52 is provided with a short arm |51 which bears against one end of an axially extending trip pin |58. The trip pin |58 ls slidably mounted in the ring |42. The oppo- 'site end of the trip pin |58 is adapted to be projected into the path of one of a series of projections |59, which extend radially from a floating ring |60. The floating ring |60 is supported by, and is free to rotate on, one end of the bearing 8 on the endframe 5 in which the sleeve |46 for the tubular stud shaft 3 is mounted and secured against axial and rotary movement, (see Fig. 7). Y

Should one of the threads y break, while the knitting machine is in operation, or become excessively slack, the trip lever |52 will be released and will be swung outwardly by centrifugal force, causing the arm |51 thereof to slide the trip pin |58 axially until said pin projects outwardly beyond the ring |60. Continued rotation of the ring |42 would cause the trip pin |56 to engage one of the projections |58 on the floating ring |60 and thereby effect rotation of said floating ring.

As shown in Fig. 12, rotation of the floating ring |60 will cause one of the projections |58 thereon to engage a lever |62, thereby effecting a rocking motion of the lever |62 about its pivot shaft |63. A lever |64, which is secured to the pivot shaft |68 of the lever |62, is connected by a link |65 to a lever |66 which is secured to the stop motion shaft |61. Also secured to the stop motion shaft |81 is a lever |68, which is connected by a link |68 to the outer end of a clutch operating lever |10. The lever is mounted on the clutch control shaft 85.

Thus, it will be seen that rotation of the floating ring |60 by one of the trip pins |58, through the mechanism just described, effects a rocking of the clutch shaft 85, and a consequent releasing of the clutch 88, by which the main shaft of the machine is released from the driving pulley 86, stopping the machine.

In order to effect rapid stopping of the machine when the clutch 88 is released, an annular brake element |1|, which is carried by the end frame 4 (see Fig. 6), is expanded into braking contact with a circular wall |12 formed in a recess in the ring gear 61. Expansion of the brake shoe |1| (see Figs. 19, 20 and 21) is effected by a substantially fiat blade |13, which is formed on the inner end of a brake operating shaft |15, and is disposed between the substantially parallel ends |14, |14 of the brake shoe |1i. The brake shaft |15 carries a lever |14, to which is secured one end of a brake spring |11.

Normally the brake applying lever |16 is held in an ineffective position by a latch |18, which bears against the under side of a block |18 secured to the lever |16. The latch |18 is secured to a short shaft |80, to which is also secured a lever |8I. The lever |8| is connected by a link |82 to a lever |83, which is secured to the stop motion shaft |61.

From the above, it will be clear that when the stop motion shaft |61 is rocked to release the clutch 88, such motion will also cause the latch |18 to move from under the block |18 on the brake lever |16, whereupon said brake lever, under the influence of the spring |11, will rotate the brake shaft |15 and effect expansion of the shoe |1| into contact with the ring gear 61, which will result in a quick stopping of the machine.

The stop motion also includes means for releasing the clutch 88 and applying the brake |1|, to stop the machine. if a needle breaks or if the knitting yarn piles up or knots at the work slot 3:. For this purpose, the machine is provided with a broken needle and knot detector |85 (see Fig. 16). This detector includes a pointed needle-like implement |86, which projects substantially into the Work slot x to be engaged by any knots or needles which may be projecting across said slot in the path of the pointed implement |86 as the cam rings 42, 42 revolve about the cylinder units A1, A.

The detecting .implement |86 is carried by a block |81, which is slidably mounted on a stud |88 carried by one of the cam rings 42. The block |81 is provided with an axial projection |88, withan outer beveled end normally seated in a notch |80 formed in the head |8| on the outer end of the stud |88.

Should the detecting implement |86, during its rotary movement about the axis of the cylinder units A1, A2, strike a broken needle or a knot in the work slot the inner end of the imple ment |86 will be stopped by such interception, while the cam ring 42 continues to revolve. Thus. the block |81 will be caused to rotate about the stud |88 and dislodge the projection |88 from the notch |90 in the stud-head |9|, bringing the projection |89 into alignment with a recess |82 of the head |9|, whereby axial movement of the block |81 relative to the stud |88 is permitted.

'The block |81 is provided with an arm |98, the outer end of which is connected to one end of a rod |94. The opposite end of the rod |94 is slidably mounted in the base ring |48 of the bobbin carrier. The rod |84 is provided with a collar |85, between which and a fixed abutment |86, carried by the second of the cam rings 42, is a spring |81. When the block |81 rotates on the stud |08, in the manner previously noted. the spring |91 slides the rod |94 axially, causing the end |99 thereof to be projected into the path of a series of lugs |99 which are formed on a floating ring 200. The ring 200 is rotatably mounted in the outer surface of a casing 20| which is secured to the end frame 4 and normally conceals the gears 61, 16, and 19.

Also projecting between the lugs |99 and the iloating ring 200 is a lever 202, which is carried by the shaft |80. When the end |98 of the trip rod |94 is projected between lugs |99 on the iloating ring 200, while the cam rings 42, 42 are revolving, the trip rod |94 will engage one of the lugs |99 and effect rotation with the ring zoo. Rotation of the ring zou wm rock the 1ever 202 and consequently the shaft |90, thereby operating the stop motion shaft |61 to throw without the clutch 88. At the same time the brake lever |16 will be released permitting the spring |11 to rotate the brake shaft |15 and thereby expand the brake shoe |1| into contact with the ring gear 61.

As shown in Fig. 22, and as previously noted, the lever |10 is mounted on the clutch controlling shaft 95. This lever, however, is not divrectly secured to said shaft, in order that the clutch control shaft 95 may be actuated manually, through the lever 96, to stop and start the machine without effecting the stop motion.

For this purpose, the lever 10 is positioned adjacent a shorter lever 203, which is-secured to the control shaft 95. The lever 203 is provided with a projection 204, which extends into an arcuate slot 205, formed in the lever |10. In this manner, the lever 203 is permitted suillcient movement relative to the lever |10 to disengage the clutch 88 without disturbing the lever |10. However, when the machine is in operation, the projection 204 of the lever 209 lies in the lower end of the slot 205 in the lever |10. Thus, any movement of the lever |10, as effected by the stop motion, will be applied to the lever 203 to rock the control shaft 95 and release the clutch.

I claim:

l. A circular knitting machine comprising a knitting head having an axial bore extending completely through said head, means supporting said head with its axis substantially horizontal, means for passing a core element axially through said bore comprising a pair of nip rolls at at least one end of said head, means foroperating said head to knit a seamless tubular covering on said core element in transit through said head, means for driving one of said nip rolls in contact with one side of said core element, means for resiliently pressing the other of said nip rolls into Contact with the opposite side of said core element to effect said advancing thereof, and means for adiusting the first of said nip rolls perpendicularly to the axis of said head to accommodate core elements of different diameters. l l

2. A circular knitting machine comprising a knitting head having an axial bore extending completely through said head, means supporting said head with its axis substantially horizontal, means for passing a core element axially through said bore, comprising a pair of nip rolls at atleast one end of said head, means for operating said head to knit a seamless tubular covering on said core element in transit through said head, means for driving said nip rolls in contact with diametrically opposite portions of said core element, means for positively adjusting one of said nip rolls to align said core element with the axis of 'said head, and means resiliently pressing the second of said nip rollsv into driving contact with said core element.

3. A circular knitting machine comprising a knitting head including a pair of axially aligned needle cylinder structures spaced apart axially to provide a work slot therebetween, a pair of tubular supports for and axially aligned respectively with said structures, a pair of spaced end` frames supporting said tubular supports with the aligned axes of said tubular supports and said structures disposed horizontally, means for passing a core element axially through said supports and said knitting head, means for operating said knitting head to knit a seamless tubular cover about said core element through Jsaid work slot during transit of said element past said slot, and means for supporting one of said tubular supports for axial movement in its supporting end frame for governing the width of the work slot between the adjacent ends of the needle cylinder structures respectively supported by said tubular supports.

4. A circular knitting machine comprising a knitting head including a pair of axially aligned needle cylinder structures spaced apart axially to provide a work slot therebetween, a pair of tubular supports for and axially aligned respectively with said structures, a pair of spaced end frames supporting said tubular supports with the aligned axes of said tubular supports and said structures disposed horizontally intermediate said end frames, rotary frictional gripping means carried on the outside of said end frames beyond the outer open ends of said tubular supports for supporting and passing a rigid core element axially through said supports and said knitting head, and means for operating said knitting head to knit a seamless tubular cover about said core element through said work slot during transit of said element past said slot.

WALTER Lmxm. 

